 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui;

 import java.util.Map ;

 import org.eclipse.jface.util.IPropertyChangeListener;

 /**
  * A part can provide arbitrary properties. The properties will be persisted
  * between sessions by the part reference, and will be available from the part
  * reference as well as the part. The properties can only be set on a part, not
  * on the reference. The properties will be available to the IPresentablePart.
  * <p>
  * Setting a property must fire a PropertyChangeEvent.
  * </p>
  *
  * @since 3.3
  */
 public interface IWorkbenchPart3 extends IWorkbenchPart2 {
     /**
      * Add a listener for changes in the arbitrary properties set.
      * <p>
      * <b>Note:</b> this is a different set of properties than the ones covered
      * by the IWorkbenchPartConstants.PROP_* constants.
      * </p>
      *
      * @param listener
      * Must not be <code>null</code>.
      */
     public void addPartPropertyListener(IPropertyChangeListener listener);

     /**
      * Remove a change listener from the arbitrary properties set.
      * <p>
      * <b>Note:</b> this is a different set of properties than the ones covered
      * by the IWorkbenchPartConstants.PROP_* constants.
      * </p>
      *
      * @param listener
      * Must not be <code>null</code>.
      */
     public void removePartPropertyListener(IPropertyChangeListener listener);

     /**
      * Return the value for the arbitrary property key, or <code>null</code>.
      *
      * @param key
      * the arbitrary property. Must not be <code>null</code>.
      * @return the property value, or <code>null</code>.
      */
     public String getPartProperty(String key);

     /**
      * Set an arbitrary property on the part. It is the implementor's
      * responsibility to fire the corresponding PropertyChangeEvent.
      * <p>
      * A default implementation has been added to WorkbenchPart.
      * </p>
      *
      * @param key
      * the arbitrary property. Must not be <code>null</code>.
      * @param value
      * the property value. A <code>null</code> value will remove
      * that property.
      */
     public void setPartProperty(String key, String value);

     /**
      * Return an unmodifiable map of the arbitrary properties. This method can
      * be used to save the properties during workbench save/restore.
      *
      * @return A Map of the properties. Must not be <code>null</code>.
      */
     public Map getPartProperties();
 }

